This is a note to let you know that I've just added the patch titled
drm/mst: Fix error handling during MST sideband message reception
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-mst-fix-error-handling-during-mst-sideband-message-reception.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 448421b5e93b9177c5698f0cf6f5e72d2995eeca Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak@xxxxxxxxx>
Date: Wed, 19 Jul 2017 14:43:28 +0300
Subject: drm/mst: Fix error handling during MST sideband message reception
From: Imre Deak <imre.deak@xxxxxxxxx>
commit 448421b5e93b9177c5698f0cf6f5e72d2995eeca upstream.
Handle any error due to partial reads, timeouts etc. to avoid parsing
uninitialized data subsequently. Also bail out if the parsing itself
fails.
Cc: Dave Airlie <airlied@xxxxxxxxxx>
Cc: Lyude <lyude@xxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
Reviewed-by: Lyude <lyude@xxxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20170719114330.26540-2-imre.deak@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2195,11 +2195,17 @@ static void drm_dp_get_one_sb_msg(struct
ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
replyblock, len);
if (ret != len) {
- DRM_DEBUG_KMS("failed to read a chunk\n");
+ DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
+ len, ret);
+ return;
}
+
ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
- if (ret == false)
+ if (!ret) {
DRM_DEBUG_KMS("failed to build sideband msg\n");
+ return;
+ }
+
curreply += len;
replylen -= len;
}
Patches currently in stable-queue which might be from imre.deak@xxxxxxxxx are
queue-4.4/drm-mst-avoid-dereferencing-a-null-mstb-in-drm_dp_mst_handle_up_req.patch
queue-4.4/drm-mst-avoid-processing-partially-received-up-down-message-transactions.patch
queue-4.4/drm-mst-fix-error-handling-during-mst-sideband-message-reception.patch